The terms “memory system” and “storage system” are generally used interchangeably herein. Existing terminology is changing as more of the on-line data and near-line data of large systems is being stored in solid state devices such as FLASH memory arrays rather than rotating disk drives. A storage system was previously considered to be primarily disk based and having data retrieval and writing latencies dominated by the mechanical performance of the disk drive. Often the disks were connected to the processor through a network connection. Memory systems were considered to be either directly attached to the processor requiring the data, or having sufficiently low latency as to cause little bottleneck in the processing speed.
As the latency of large FLASH memory arrays is considerably less than that of disks, yet the storage capacity and economics of such FLASH memory arrays is beginning to compete directly with disk-based systems, the distinction between a “memory system” and a “storage system” is somewhat blurred. Here we use the terms to describe a solid-state memory system, whether connected to the using server directly or through some network connection. The term network connection is intended to encompass all forms of data communications.